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authorWen Gu <guwen@linux.alibaba.com>2022-09-20 17:52:21 +0800
committerPaolo Abeni <pabeni@redhat.com>2022-09-22 12:58:21 +0200
commit77eee32514314209961af5c2982e871ecb364445 (patch)
tree36a7bf8259b6498405019cf715c2894265b6737f /net/smc
parent9b17dbd97de78796997583340b540bdb571694e6 (diff)
downloadlinux-77eee32514314209961af5c2982e871ecb364445.tar.gz
net/smc: Introduce a specific sysctl for TEST_LINK time
SMC-R tests the viability of link by sending out TEST_LINK LLC
messages over RoCE fabric when connections on link have been
idle for a time longer than keepalive interval (testlink time).

But using tcp_keepalive_time as testlink time maybe not quite
suitable because it is default no less than two hours[1], which
is too long for single link to find peer dead. The active host
will still use peer-dead link (QP) sending messages, and can't
find out until get IB_WC_RETRY_EXC_ERR error CQEs, which takes
more time than TEST_LINK timeout (SMC_LLC_WAIT_TIME) normally.

So this patch introduces a independent sysctl for SMC-R to set
link keepalive time, in order to detect link down in time. The
default value is 30 seconds.

[1] https://www.rfc-editor.org/rfc/rfc1122#page-101

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net/smc')
-rw-r--r--net/smc/smc_llc.c2
-rw-r--r--net/smc/smc_llc.h1
-rw-r--r--net/smc/smc_sysctl.c9
3 files changed, 11 insertions, 1 deletions
diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
index 175026ae33ae..524649d0ab65 100644
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -2127,7 +2127,7 @@ void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc)
 	init_waitqueue_head(&lgr->llc_flow_waiter);
 	init_waitqueue_head(&lgr->llc_msg_waiter);
 	mutex_init(&lgr->llc_conf_mutex);
-	lgr->llc_testlink_time = READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time);
+	lgr->llc_testlink_time = READ_ONCE(net->smc.sysctl_smcr_testlink_time);
 }
 
 /* called after lgr was removed from lgr_list */
diff --git a/net/smc/smc_llc.h b/net/smc/smc_llc.h
index 4404e52b3346..7e7a3162c68b 100644
--- a/net/smc/smc_llc.h
+++ b/net/smc/smc_llc.h
@@ -19,6 +19,7 @@
 
 #define SMC_LLC_WAIT_FIRST_TIME		(5 * HZ)
 #define SMC_LLC_WAIT_TIME		(2 * HZ)
+#define SMC_LLC_TESTLINK_DEFAULT_TIME	(30 * HZ)
 
 enum smc_llc_reqresp {
 	SMC_LLC_REQ,
diff --git a/net/smc/smc_sysctl.c b/net/smc/smc_sysctl.c
index 0613868fdb97..3224d303cc9d 100644
--- a/net/smc/smc_sysctl.c
+++ b/net/smc/smc_sysctl.c
@@ -16,6 +16,7 @@
 
 #include "smc.h"
 #include "smc_core.h"
+#include "smc_llc.h"
 #include "smc_sysctl.h"
 
 static struct ctl_table smc_table[] = {
@@ -35,6 +36,13 @@ static struct ctl_table smc_table[] = {
 		.extra1		= SYSCTL_ZERO,
 		.extra2		= SYSCTL_TWO,
 	},
+	{
+		.procname	= "smcr_testlink_time",
+		.data		= &init_net.smc.sysctl_smcr_testlink_time,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_jiffies,
+	},
 	{  }
 };
 
@@ -60,6 +68,7 @@ int __net_init smc_sysctl_net_init(struct net *net)
 
 	net->smc.sysctl_autocorking_size = SMC_AUTOCORKING_DEFAULT_SIZE;
 	net->smc.sysctl_smcr_buf_type = SMCR_PHYS_CONT_BUFS;
+	net->smc.sysctl_smcr_testlink_time = SMC_LLC_TESTLINK_DEFAULT_TIME;
 
 	return 0;